Condensation products of diamines and fatty acids



Patented Aug. 22, 1350 UNITED STATES PATENT OFFICE 'CONDENSATION PRODUCTS OF DIAMINES AND FATTY ACIDS Philip F. Tryon, Terre Haute, Ind., assignor to Commercial Solvents Corporation, Terre Haute, Ind., a corporation of Maryland No Drawing. Application September 3 1946, Serial No. 694,679

3 Claims.

wherein R is hydrogen, alkyl, oralkenyl, with N-mono-substituted 1,2-alkanediamines having the structure R NH-CH2 J--R NE: in which R is alkyl, cyc1oalkyl,.aryl, alkaryl, aralkyl, furfuryl, or tetrahydrofurfuryl, and R and R are hydrogen or akyl groups, said reaction products comprising imidazolines having the structure wherein the substituent groups are as defined above, and combinations of said imidazolines in 1:1 or 1:2 molar ratio with the fatty acid from which they are derived. The exact structure of the imidazoline-fatty acid combination is unknown, and for convenience the combination will be referred to as the association product or the complex of the imidazoline with the fatty acid from which it is derived.

Broadly, my invention comprises the product obtained by heating a mixture of a fatty acid with an N-monosubstituted 1,2-alkanediamine, as disclosed above, until up to two moles of water have been removed per mole of diamine.

In a more specific embodiment, my invention comprises the reaction product obtained by heating a mixture containing a fatty acid and an N-monosubstituted 1,2-alkanediamine, as disclosed above, in a molar ratio of one or more until up to two moles of water per mole of diamine have been removed.

In another specific embodiment, the said reaction products of fatty acids and diamines, as disclosed above, are combined with a mineral acid, such as hydrochloric acid, sulfuric acid, or phosphoric acid, the mineral acid preferably being used in equimolecular ratio to the quantity of imidazoline present in the said reaction product.

In a further embodiment, the said reaction products of fatty acids and diamines, as disclosed above, are combined with additional fatty acid, either the same or a different fatty acid, preferably in such quantity that the resulting combination contains imidazoline and total fatty acids in equimolecular proportion.

The products of my invention. are useful for numerous purposes; for example, they are surface-active compounds and may be used as detergents, emulsifying agents, clean-sing agents, protective agents, softening agents for textiles, etc., and may be incorporated in cutting oils, lubricants, sizing materials, cleaning and scouring compositions, floor waxes, and the like.

Among the diamines suitable for preparing the products of my invention are the following: N- (2-aminoisobutyl) butylamine, N- (2-amino-2- methylbutyl) -1-methylisopentylamine, N- (2- aminoethyl) -1-methylpropylamine, N-(Z-aminobutyl) octylamlne, N- (2-aminopropyl) octadecylamine, N- (Z-aminoisobutyl) aniline, N- (Z-aminoisobutyl) o-toluidine, N-(2-aminoisobutyl) -mtoluidine, N- (Z-aminoisobutyl) -p-toluidine, N- (2- aminoisobutyl) xylidines, N- (Z-aminoisobutyl) benzylamine, N- (Z-aminoisopentyl) -furfurylamine, and N- (Z-aminohexyl) tetrahydrofurfurylamine.

Among the suitable fatty acids are the following: Formic, acetic, propionic, butyric, isobutyric, valeric, caprolc, lauric, myristic, palmitic, stearic, and oleic.

In preparing the products of my invention, I mix a fatty acid and a diamine chosen from the type disclosed above, preferably in the ratio between about 1 and 3 moles of fatty acid per mole of diamine. I then add a small proportion of an organic liquid suitable for separating the water of reaction as an azeotrope, and subsequently heat the mixture to reflux in a suitable still, liquid temperatures between about and 250 C. ordinarily being required. The reaction is usually carried out at atmospheric pressure, but superatmospheric pressures may be used if desired, in order to produce a higher liquid temperature during the reflux period, particularly when low-boiling fatty acids are being processed. Higher temperatures tend to reduce the time required to complete the reaction, but temperatures high enough to produce substantial decomposition and degradation of the reacting materials and products should not be used. As the reaction proceeds, the water of reaction is distilled as an azeotrope, and is separated from the distillate, While the azeotrope-former is returned to the still. The reaction maybe stopped at any intermediate point, but is ordinarily continued until between about 1 and 2 moles of water have been distilled per mole of diamine. After the reaction has been carried as far as desired, the remaining azeotrope-former is distilled out, and the unreacted diamine and fatty acid are ordinarily removed by distillation or crystallization. The residue then remaining in the still comprises the desired imidazoline products, which may be used as such, or may be further purified by distillation at low pressure.

The reaction may also be carried out in a continuous apparatus. The mixture of diamine and fatty acid may be reacted, for example, by passage through a heated coil, and the mixture discharged into a fractionating column into which an azeotrope-forming substance is continuously added. The water is removed overhead and the reaction products are withdrawn from the bottom of the column. A furtherseparation may be carried out by removing the unreacted diamine and fatty acid as side cuts from the fractionating column and vacuum-distilling the residue in order to separate the imidazoline products.

The reaction product. after removal of the azeotrope-former and the unreacted diamine and fatty acid, ordinarily comprises mainly the imidaaoline derivable from the diamine and fatty acid and various complexes or association products of the imidazoline with the fatty acid. It is ordinarily unnecessary to separate these materials from one another, but the separation can be accomplished, as described above, by a fractional distillation under vacuum. Such separation, however, is unnecessary in most of the applications for which the products of my invention are adapted. For example, the hydrochloric acid salts of the crude products, prepared as described above, are exceptionally effective surface-active agents, particularly suited for the softening of various fabrics; and mixtures of the crude products with additional fatty acids are excellent detergents. Also, the association product of the imidazoline with the fatty acid may be processed to release the free imidazoline by treatment with an alkaline material such as an alkali-metal hydroxide. The free imidazoline may then be extracted and purified by known means, such as by crystallization or distillation. The purified imidazoline and its fatty-acid and mineral-acid derivatives are useful in all the applications detailed above.

Contrary to what would be expected, I have not been able to detect any amides in the products of my invention.

The following examples are offered in order to show the processing of certain specific diamines and fatty acids, but are not intended to limit the scope of the invention. to the exact materials shown. All of the experiments were carried out by heating a mixture of the diamine, the fatty acid, and benzene to reflux in a flask equipped with a fractionating column and a decanter head arranged to drain on the water layer of the distillate and return the benzene layer to the column. After the dehydration reaction had been carried to the desired point, the unreacted diamine was distilled ofl under vacuum, and the products were refined by crystallization or by distiliation at pressures of 30 mm. of mercury or below.

EXAMPLE I One-sixth gram-mole of N-(2-aminoisobutyl) mopmpvlamine was mixed with one-half mole of formic acid of 98% purity and a small quantity of benzene, and the mixture was heated at a liquid temperature of 140 to 150 C. for four hours, during which time 0.33 mole of water was removed. The product comprised 0.131 mole of 4,4-dimethyl-l-isopropyl-2-imidazoline and 3.9 grams of association products of the imidazoline with formic acid.

EXAMPLE II N-(Z-aminoisobutyl) isopropylamine was mixed in equimolecular proportion with acetic acid and refluxed with a small quantity of benzene at a liquid temperature of 190 to 200 C. for three hours, during which time 1.2 moles of water per mole of diamine were removed. The product was distilled under vacuum to separate l-isopropyi- 2,4,4-trimethyl-2-imidazoiine in 23% conversion, and a'complex of 1-isopropyl-2,4.4-trimethyl-2- imidazoline with two molecules of acetic acid in 33% conversion, based on the diamine initially charged into the reaction vessel.

The imidazoline is soluble in ether. It is pre cipitated from ether by dry hydrogen chloride as a white solid which changes to an oil.

The association product of the imidazoline with acetic acid is soluble in water, ethanol, benzene, and carbon tetrachloride, gives a turbid mixture with acetone, and is insoluble in ether and petroleum ether. It reacts exothermieally with hydrochloric acid to form an addition product, and with sodium hydroxide to give the free imidazoline.

When the proportion of acetic acid in the reactant mixture is increased to three moles of acid to one mole of diamine and the reaction is continued until the formation of water has stopped, conversion of the diamine to the association product of the imidazoline and acetic acid is complete.

EXAMPLEHI One mole of N-(2-aminoisobutyl)isopropylamine was heated with one mole of butyric acid at to C. until one mole of water had been removed, flve hours being required. Distillation of the reaction product under vacuum gave a 39% recovery of unconverted diamin a 19% conversion to 4,4-dimethyl-1-isopropy1-2-propyl- 2-imidazoline and an 18% conversion to the imidazoline complex with butyric acid.

EXAMPLE IV N-(2-aminoisobutyl)isopropylamine was heated at 165 to 175 C. with isobutyric acid in equimolecular proportion until one mole of water per mole of diamine had been removed, six hours bein; required. The products were 4,4-dimethyl- 1,2-dilsopropyl-2-imidazoline and a complex of the imidazoline with isobutyric acid, the latter being formed in approximately 10% conversion, based on the diamine.

EXAMPLEV An equimolecular mixture of N-(2-aminoisobutyl) isopropylamine and caproic acid was heated until one mole of water had been removed per mole of diamine. From the reaction product were separated 4,4-dimethyl-l-isopropyl-2-pentyl-2-imidazoline in 15% conversion, based on the diamine, and a complex of the imidazoline with caproic acid in 22% conversion.

A quantity of the crude reaction product was combined with lauric acid in equimolecuiar ratio to the diamine initially used, and the combination was found to be an effective detergent.

EXAMPLEVI N-(2-aminoisobutyl) isopropylamine was heated with an equimolecular proportion of lauric acid at to 200 C. for three hours, during which time one mole of water per mole of diamine was removed. A very small quantity of 4,4-dimethyl-2-hendecyl-l isopropyl 2- imidazoline was formed. The principal reaction product was the complex of the imidazoline with lauric acid, which was produced in 29% conversion, based on the diamine.

5. EXAMPLE N (Z-aminoisobutyl) isopropylamine was heated with palmitic acid in equimolecular proportion at 200 to 210 C. for two and one-half hours, during which time one mole ofwater per mole of diamine was removed. The product was distilled and a complex of 4,4-dimethyl-l-isopropyl-2- pentadecyl-2-imidazoline was separated in over 30% conversion, based on the diamine. This was substantially quantitative, in view of the diamine-to-acid ratio that was used.

EXAMPLE VIII N-(2-aminoisobutyl) isopropylamine was heatedwith stearic acid in equimolecular proportion at 190 to 200 C. for three hours, during which time one mole of water per mole of diamine was removed. Distillation of the product showed a substantially quantitative conversion of the diamine into a complex of 4,4-dimethyl-2-heptadecyi-1-isopropyl-2-imidazoline with stearic acid.

The above product, when combined with hydrochloric acid in an amount molecularly equivalent to the amount of diamine employed in its manufacture, was converted into an effective softening and finishing agent for textiles.

EXAMPLEIX EXAMPLE X N-(2-aminoisobutyl)-m-toluidine was heated with acetic acid in equimolecular proportion at 190 to 210 C. for four hours, during which time two moles of water per mole of diamine was removed. On distillation, the principal product was found to be 1-m-tolyl-2,4,4-trimethyl-2-imidazoline, which was produced in 75.9% conversion, based on the diamine.

EXAMPLEXI N- (2 aminoisobutyl) tetrahydrofurfurylamine was heated with stearic acid in equimolecular proportion at to 225 C. for six hours, during which time one mole of water per mole of diamine was removed. The product, comprising 4,4-dimethyl-2-heptadecyl-1 tetrahydrofurfuryl 2- imidazoline and stearic acid association products, was a dark-brown oil which set to a viscous suspension of solids.

EXAMPLE XII N-(2-aminoisobutyl)butylamine was heated with stearic acid in equimolecular proportion at to 210 C. for three hours, during which time one mole of water per mole of' diamine was removed. On distillation of the product, an equimolecular association product or 1-butyl-4,4-dimethyl-2-heptadecyl-2-imidazoline and stearic acid was separated in 43.5% conversion, based on the diamine.

EXAMPLEXIH N (2 amino-2-methylbutyl)-1-methylisopentylamine and acetic acid were mixed in 1:3 molar ratio, and the mixture was heated in the presence of a small quantiy of benzene at 170 to 200 C. for four hours, during which time two moles of water per mole of diamine were removed. On distillation, the principal product was tound to be an association product of 2,4-dimethy1- 2-ethyl-1-(l-methylisopentyl) 2 imidazoline with two molecules of acetic acid. The conversion to the principal product was 80%, based on the diamine.

The properties of some of the imidazolines of my invention and their fatty acid association products are listed in the following two tables.

TABLE I Properties of imidazolines l-Methyl-propyl (1 n l-Methyl-isopentyl Phen l m-Toly p-Tolyl.

are. "in". LEW-40.

TABLE II Properties of complexes of fatty acids with imidczolines derivable therefrom i R-O O nR-OOOH R N- H:

B. P. n R R B a -5;- a: c. an"

0. mm. Hg

R 1.0.1 1, CH- CH" 2 155-156 30 CH do do do..- 2 124-125 1.020 1.4000 C1H do do do 2 129-130 1.11112 1.4610 C1111 do do 4' n 2 106-109 2 0. 0759 1. 4600 1-C1H do do do"--. 2 128-132 20 0.9744 1.4688 C Hg d f n 2 150 22 0. 9525 1. 4601 0.1; do do n 2 157-160 20 11Ha do n 2 160-162 1 0 B. do do d 2 206-119 6 c H dn do do 2 44-45 CnHu. dn 1 n (in 2 537.209 1 54455 CH; l-Methyl-propyl m do 2 134-136 26 C11Hu.-- 0 d0 2 213-216 2 49-49. 5 CH; C 11- rn dn 2 134-136 26 C|7H]l---- 0 ...d0 1 2202% 2 0H; l-Methyl-isopentsl... .-.do 01111."- 2 139-141 26 (111 15.--. do do do 1 219-221 2 Do Phenyl (10 (FL 1 4043 Do m-Tolyl do do 1 63-66 While the foregoing examples illustrate the preferred embodiments 01' my invention, it is to be understood that departures may be made therefrom within the scope of the specification and claims. In general it may be said that any modifications or equivalents that would ordinari- 1y occur to those skilled in the art are to be considered as lying within the scope of my invention.

I claim as my invention:

1. A composition of matter comprising an association product of a fatty acid with an imidazoline derivable from said fatty acid, in admixture with a quantity of said imidazoline in unassociated form, said imidazoline having the structure wherein R is a member selected from the group consisting of hydrogen. alkyl, and alkenyl; R is In accordance with the foregoing specification,

a member selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl, aralkyl, furfuryl, and tetrahydrofurturyl; and R and R are members selected from the group consisting of hydrogen and alkyl.

2. The composition 01 claim 1, in combination with a mineral acid.

3. The composition of claim 1, in combination with a fatty acid.

PHILIP F. TRYON.

REFERENCES crrnp The following references are of record in the file of this potent:

UNITED STATES PATENTS Number Name Date 2,194,419 Chwala May 19, 1940 2,215,861 Waldmann et al. Sept. 20, 1940 2,392,326 Kyrides Jan. 8. 1946 2,393,825 Senkus Jan. 29, 1946 2,418,077 Kyrides Mar. 25, 1947' 2,446,522 Bockmuhl et al. Aug. 10, 1948 Certificate of Correction Patent No. 2,520,102 August 22, 1950 PHILIP TRYON K It is hereby certified that error appears in the printed specification of the'above numbered patent requiring correctlon as follows:

Column 1, line 17, for fakyl read alkyl; column 6, line 34, for quantiy read quantity; columns 7 and 8, in the table, 9th column thereof, for the heading and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 5th day of December, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

1. A COMPOSITION OF MATTER COMPRISING AN ASSOCIATION PRODUCT OF A FATTY ACID WITH AN IMIDAZOLINE DERIVABLE FROM SAID FATTY ACID, IN ADMIXTURE WITH A QUANTITY OF SAID IMIDAZOLINE IN UNASSOCIACTED FORM, SAID IMIDAZOLINE HAVING THE STRUCTURE 